Technology for backing up CDs using compression CODEC such as MP3 is, ironically, becoming a threat to the profits of copyright holders of the content. This is because the act of distributing audio data which is obtained for making a backup (hereinafter “backup audio data”) through the Internet and so on without the authorization of the copyright holder occurs throughout the world. In light of such circumstances, SDMI (Secure Digital Music Initiative) specifies the following two methods for backing up packaged contents that are recorded on a CD.
In the first method, a license management apparatus makes a backup of the CD, and in the second method a portable device makes a backup of the CD. A license management apparatus is equipment such as a personal computer that is equipped with software which is called a licensed compliant module (hereinafter “LCM”). A portable device (hereinafter “PD”) is an audio device that is not equipped with an LCM. The LCM in a license management apparatus allows the license management apparatus to perform the function of managing audio data that is obtained by backing up. In detail, the license management apparatus performs the function of generating and updating copyright management information about backup audio data. In contrast, since a PD does not have an LCM, the PD does not perform such a management function, but is limited to performing functions such as recording and playback of audio data. Both PDs and license management apparatuses encrypt, by using a predetermined encryption key, audio data which is obtained by compression coding of packaged contents, and then record the audio data on a recording medium. In principle, PDs and license management apparatuses prohibit copying of audio data from the recording medium to another recording medium. Consequently, it is not possible for backup audio data to be sold over a network. Check-in and check-out procedures which are performed by the license management apparatus are an exception to this principle of copy prohibition. Check-out, just as a guest leaves a hotel, is the act of recording backup audio data which is managed in the license management apparatus on a portable recording medium such as a semiconductor memory card. According to this, backup audio data can be transferred from the license management apparatus and can be used in a PD. Conversely, check-in, as if to call the guest back to the hotel, is the act of returning the backup audio data which is recorded on the portable recording medium to the license management apparatus. By returning the audio data which is recorded on the portable recording medium to the license management apparatus, the portable recording apparatus can be used to store other audio data.
However, since PDs cannot perform right management, when a backup is performed in a PD, exceptional copying such as check-in and check-out cannot be performed. This gives rise to a problem that the user is given an impression that usability is poor as compared to technology which makes a backup by using a license management apparatus.